Working under the Pennsylvania Committee of Defense, chaired by Benjamin Franklin, Kosciuszko designed Pennsylvania's defensive works on the Delaware River, including three bands of underwater obstacles. Already occupying Philadelphia, the British began bombarding Fort Mifflin on October 10, 1777, and by mid November, after heroic American resistance, had overrun all three of the city's river defenses.This map, published by William Faden in 1779, shows some of the American defenses, including the lower stockade across the river, and the American forts at Red Bank and Mud Island.